APU-1 Emulation Stutter

[bgott]

Background:

16197427 BJYK $0D Mask
350 TBI 4x4 Suburban 4L60E w/ Moates APU-1 in simultaneous emulation/datalog mode.

The engine is essentially stock with the exception of a Summit K1102 Camshaft. Currently running a stock tune and it runs OK. For those of you who have read my other posts, I am trying to tune this engine to get a feel for how to do so before spending money building my next engine and not understanding how to tune and damaging it. FULL DISCLOSURE: this engine has either a blown head gasket or cracked head. It has not affected performance much but it is something that could be skewing my results and causing me issues.

Running the bins attached with the APU-1 I have in emulation mode with any bins I have and I have issues at idle with huge dips in RPM/SA/BLM/etc.

Basically what I have tried to do is start with the stock bin and ensure that it emulates without issue for the truck with a stock L05. Running the unmodified BIN or any others I have tried still results with this issue so I am wondering if it is a communication issue between the laptop/apu-1 or the apu-1/ECU. It's almost like it loses connection for a second and then recovers. It seems to be a non-issue while cruising.

Attached are the logs. As I am new to this any help is appreciated. There are also two logs with the Stock Tune if it may help to compare them to the emulated BIN.

[bgott]

Background:

16197427 BJYK $0D Mask
350 TBI 4x4 Suburban 4L60E w/ Moates APU-1 in simultaneous emulation/datalog mode.

The engine is essentially stock with the exception of a Summit K1102 Camshaft. Currently running a stock tune and it runs OK. For those of you who have read my other posts, I am trying to tune this engine to get a feel for how to do so before spending money building my next engine and not understanding how to tune and damaging it. FULL DISCLOSURE: this engine has either a blown head gasket or cracked head. It has not affected performance much but it is something that could be skewing my results and causing me issues.

Running the bins attached with the APU-1 I have in emulation mode with any bins I have and I have issues at idle with huge dips in RPM/SA/BLM/etc.

Basically what I have tried to do is start with the stock bin and ensure that it emulates without issue for the truck with a stock L05. Running the unmodified BIN or any others I have tried still results with this issue so I am wondering if it is a communication issue between the laptop/apu-1 or the apu-1/ECU. It's almost like it loses connection for a second and then recovers. It seems to be a non-issue while cruising.

Attached are the logs. As I am new to this any help is appreciated. There are also two logs with the Stock Tune if it may help to compare them to the emulated BIN.

Well I managed to find a workaround temporarily, and it does seem that the emulation is causing this. I took the same BIN, a custom tune I had made with different fueling tables, and burned it to a chip using flash'n'burn and the tune worked seamlessly when using the G1 adapter. I verified the tune against the BIN file using flash'n'burn and also TunerPRO RT's compare function (downloaded the BIN from the chip after burning and used the function).

So, if anyone else is having a similar issue to this using the APU-1 this works as a workaround. I left a voicemail for Moates and will post back once I find out if there is any rhyme or reason to this issue with emulation. I am pleased with the performance of the bin so far, granted I haven't dyno'd it or anything, but it does feel a bit better and seems to idle a bit smoother.

[57 Handyman]

For clarification, are you saying the comms link between your APU1 and computer goes down for a brief period and you lose data then it starts back up without your intervention? How are you connected to your vehicle via ALDL? I ask because I had similar experience using TPRT and APU1 via the ALDL and attributed it to my jury-rigged/weird wiring between the fixed ALDL and APU1 connector.

A while back, in response to my inquiry about similar disconnect experience, Dave W mentioned that only 3 Pins (A, B, and E wire moved to M) on the ALDL need to be connected to the APU1 connector. In order to ONLY have 3 inputs to the APU, I used jumpers between the ALDL and the APU connector. Try taking a look at that connection point and get back to us.

[bgott]

For clarification, are you saying the comms link between your APU1 and computer goes down for a brief period and you lose data then it starts back up without your intervention? How are you connected to your vehicle via ALDL? I ask because I had similar experience using TPRT and APU1 via the ALDL and attributed it to my jury-rigged/weird wiring between the fixed ALDL and APU1 connector.

A while back, in response to my inquiry about similar disconnect experience, Dave W mentioned that only 3 Pins (A, B, and E wire moved to M) on the ALDL need to be connected to the APU1 connector. In order to ONLY have 3 inputs to the APU, I used jumpers between the ALDL and the APU connector. Try taking a look at that connection point and get back to us.

I am connected in the "simultaneous datalogging and emulation mode" specified by moates. They have a proprietary ALDL cable with a CAT5 end that plugs into the APU-1/OPD1 port and then the emulation cable from the APU-1 goes to the ECU. Then, the APU-1 is connected via USB to my datalogging/emulating laptop. As this cable has the cat 5 termination are you suggesting I dissect it and then jumper the wires? I don't mean to sound sarcastic, I'm being serious. I know there are several variations of the APU-1 in existence. IE some have serial ALDL cables some have the CAT5 version.

Basically, it's more or less that the connection drops for a split second and then recovers the next. The engine shutters but doesn't stall and there doesn't seem to be a rhythmic pattern. These errors don't seem to occur singularly, that is they don't only ever happen once in a short time. Typically it is a short burst of them, maybe two or three. They are not in rhythm however. The logs show this a bit.

Again, I have a workaround in the interim that is working successfully and really I don't have a specific need for the emulation, but it would be nice as opposed to having to burn chips.

[stew86MCSS396]

It was dave w that suggested to connect only to those 3 pins^^^...as I was perusing the internet stumbled on this pic...

No need to butcher your store bought cable.

...however @57 Handyman Your last log seemed to have those occasional disconnects as well but I don't seem to recall the engine acting accordingly. Hmmm...come to think of it...do you need to have pin b connected???

[bgott]

It was dave w that suggested to connect only to those 3 pins^^^...as I was perusing the internet stumbled on this pic...

No need to butcher your store bought cable.

...however @57 Handyman Your last log seemed to have those occasional disconnects as well but I don't seem to recall the engine acting accordingly. Hmmm...come to think of it...do you need to have pin b connected???

Hmmm. I'll have to try that if I still can't get it to work. I don't really neeeeeed the realtime emulation, but considering I paid a premium for the feature it would be nice.

The tune is running pretty well. My BLMs are down from 150 at certain points and are getting towards the low to mid 140s at worst. You can tell where I spend most of my time driving the truck as it is actually darn near perfect, it is hovering around 127.5. Some of the areas where I don't spend much time are still not great. Due to the area I drive it's a bit hard to get some of the combinations of RPM and MAP readings. Does anyone have any suggestion for how to extrapolate these data points? I have read before a post by eagle-mark about basically ignoring the data points with less than a certain number of counts. In addition to this, I am aware of the smoothing command and am assuming that I could do that for nearby cells to where most of my driving is done. For example the cell at 2000 RPM and 60 KPa is likely to be pretty close to 2000 RPM 80 KPA and 2400 RPM and 60 KPa.

Also, thinking the spark tables likely need adjusted for this cam. The same grind Edelbrock Cam (2102 Edelbrock vs 1102 Summit) calls for 14° Initial timing and no more than 32° total advance at 3500 RPM. I am assuming running it at stock TBI initial timing with the stock tables isn't getting me the performance I want. Any suggestions?